Electric vehicle propulsion and charging system

Abstract

A motor vehicle includes an AC (alternating current) electric motor having a stator with a plurality of stator windings, a rechargeable source of stored electrical energy, and an inverter coupled to the rechargeable source of stored electrical energy and to the AC electric motor. The system also includes one or more controllers collectively programmed to switch the inverter to provide alternating current propulsive energy from the rechargeable source of stored electrical energy to the plurality of stator windings and, using at least one of the stator windings as a boost inductor, switch the inverter to step up a voltage at a charging input coupled to the inverter to charge the rechargeable source of stored electrical energy.

What is claimed is: 
     
         1 . A motor vehicle comprising:
 an AC (alternating current) electric motor having a stator with a plurality of stator windings;   a rechargeable source of stored electrical energy;   an inverter coupled to the rechargeable source of stored electrical energy and to the AC electric motor;   one or more controllers collectively programmed with the following instructions:
 switch the inverter to provide alternating current propulsive energy from the rechargeable source of stored electrical energy to the plurality of stator windings; and 
 using at least one of the stator windings as a boost inductor, switch the inverter to step up a voltage at a charging input coupled to the inverter to charge the rechargeable source of stored electrical energy. 
   
     
     
         2 . The motor vehicle of  claim 1 , wherein the rechargeable source of stored electrical energy comprises a battery. 
     
     
         3 . The motor vehicle of  claim 2 , wherein the inverter is an inverter with greater than two output voltage levels. 
     
     
         4 . The motor vehicle of  claim 2 , wherein the inverter is a two-level inverter. 
     
     
         5 . The motor vehicle of  claim 2 , wherein:
 the plurality of stator windings comprises a first set of WYE-connected three-phase stator windings and a second set of WYE-connected three-phase stator windings, the first set of WYE-connected three-phase stator windings having a first neutral point and the second set of WYE-connected three-phase stator windings having a second neutral point;   the AC electric motor vehicle further comprises a switchable contact interposed between the first neutral point and the second neutral point; and   the one or more controllers are further collectively programmed with the following instructions:
 cause the switchable contact to be open while the inverter is switched to provide alternating current propulsive energy from the rechargeable source of stored electrical energy to the plurality of stator windings; and 
 cause the switchable contact to be closed while the inverter is switched to step up a voltage at the charging input to charge the rechargeable source of stored electrical energy. 
   
     
     
         6 . The motor vehicle of  claim 2 , wherein:
 the charging input is switchably coupled to the inverter by a switchable contact; and   the one or more controllers are further collectively programmed with the following instruction:
 cause the switchable contact to be closed while the inverter is switched to step up a voltage at the charging input to charge the rechargeable source of stored electrical energy. 
   
     
     
         7 . The motor vehicle of  claim 2 , wherein the AC electric motor is a six-phase AC electric motor. 
     
     
         8 . The motor vehicle of  claim 2 , wherein:
 the instruction to switch the inverter to step up a voltage at the charging input to charge the rechargeable source of electrical energy further comprises an instruction to perform two-phase interleaved step-up conversion.   
     
     
         9 . A method for controlling an electric vehicle propulsion and charging system, the method comprising:
 switching an inverter to provide alternating current propulsive energy from a rechargeable source of stored electrical energy to a plurality of stator windings of an AC (alternating current) electric motor; and   using at least one of the stator windings as a boost inductor, switching the inverter to step up a voltage at a charging input coupled to the inverter to charge the rechargeable source of stored electrical energy.   
     
     
         10 . The method of  claim 9 , wherein the rechargeable source of stored electrical energy comprises a battery. 
     
     
         11 . The method of  claim 10 , wherein the inverter is an inverter with greater than two output voltage levels. 
     
     
         12 . The method of  claim 10 , wherein the inverter is a two-level inverter. 
     
     
         13 . The method of  claim 10 , wherein:
 the plurality of stator windings comprises a first set of WYE-connected three-phase stator windings and a second set of WYE-connected three-phase stator windings, the first set of WYE-connected three-phase stator windings having a first neutral point and the second set of WYE-connected three-phase stator windings having a second neutral point;   the electric vehicle propulsion and charging system further comprises a switchable contact interposed between the first neutral point and the second neutral point;   the method further comprises causing the switchable contact to be open while the inverter is switched to provide alternating current propulsive energy from the rechargeable source of stored electrical energy to the plurality of stator windings; and   the method further comprises causing the switchable contact to be closed while the inverter is switched to step up a voltage at the charging input to charge the rechargeable source of stored electrical energy.   
     
     
         14 . The method of  claim 10 , wherein:
 the charging input is switchably coupled to the inverter by a switchable contact; and   wherein the method further comprises causing the switchable contact to be closed while the inverter is switched to step up a voltage at the charging input to charge the rechargeable source of stored electrical energy.   
     
     
         15 . The method of  claim 10 , wherein the AC electric motor is a six-phase AC electric motor. 
     
     
         16 . The method of  claim 10 , wherein:
 switching the inverter to step up a voltage at the charging input to charge the rechargeable source of stored electrical energy comprises performing two-phase interleaved step-up conversion.   
     
     
         17 . A motor vehicle comprising:
 an AC (alternating current) electric motor having a stator with a plurality of stator windings, the plurality of stator windings comprising a first set of WYE-connected three-phase stator windings having a first neutral point and a second set of WYE-connected three-phase stator windings having a second neutral point, the AC electric motor further comprising a switchable contact interposed between the first neutral point and the second neutral point;   a rechargeable source of stored electrical energy;   an inverter coupled to the rechargeable source of stored electrical energy and to the AC electric motor; and   one or more controllers collectively programmed with the following instructions:
 cause the switchable contact to be open and switch the inverter to provide alternating current propulsive energy from the rechargeable source of stored electrical energy to the plurality of stator windings; and 
 cause the switchable contact to be closed and, using at least one of the stator windings as a boost inductor, switch the inverter to step up a voltage at a charging input coupled to the inverter to charge the rechargeable source of stored electrical energy. 
   
     
     
         18 . The motor vehicle of  claim 17 , wherein:
 the charging input is switchably coupled to the inverter by a second switchable contact; and   the one or more controllers are further collectively programmed with the following instruction:
 cause the second switchable contact to be closed while the inverter is switched to step up a voltage at the charging input to charge the rechargeable source of stored electrical energy. 
   
     
     
         19 . The motor vehicle of  claim 18 , wherein the instruction to switch the inverter to step up a voltage at the charging input to charge the rechargeable source of electrical energy further comprises an instruction to perform two-phase interleaved step-up conversion. 
     
     
         20 . The motor vehicle of  claim 19 , wherein the inverter is a two-level inverter.